Well…practice makes perfect…the more and more you start trying to play offensively, putting yourself out for those risks and trying to run the match you’ll get better at being on offense and running the match. Play through it, I guess is my advice.

Well you pretty much have to read your opponent, especially against reversal characters, bait those out, and max punish.
With close range footsies, frame data becomes much more important. You need to know what comes out faster, recovers faster, good hitboxes, leaves you at neutral or advantage on block, and give you combo opportunity. If youre being stuffed by normals, then you should get a rough idea of what the frame data and hitboxes of your char is.

This is a fairly broad topic and fairly character specific but a couple notes on starting offense:

Footsies in the grand scheme of things in the art of getting in on someone [potentially, not everyone cares in the end of it]. This has two main facets in my mind. That a person cannot feasibly halt every option and that their attempts to halt your advance implies a sort of risk. The first one suggests that no one has a rock solid defense - it can be difficult to get in, but if you’re patient about your advances eventually you’ll slip in through the cracks. A good example is when people are hovering around jump in range looking for something to shoryu. So you advance on the ground and they’ll slip back slightly trying to get back into range. Eventually when it becomes clear you’re not gonna jump it might be too late and you’re on top of them. Similarly if they’re looking for you to dash or walk they might miss the jump. The reason this is char specific is that some chars can mess up ranges easily letting them advance better.[DKs,dash walk speed, IATs, advancing moves, etc] The other facet can more or less be summed up in counter poking. If they stick something out preemptively, hit the limb or take the moment to dash in/walk in/jump in.

Once on the actual offensive knowing your frames can help a lot. 2f perfect traps cannot be halted by normals so you’ll force them to BD, reversal or block. An example Makoto s.mp s.lp. +2 -> 4 frame move, they’re stuck. If you get them to stand still because of that, go for a throw, more pressure etc. This forces them to take a risk, get closer to the corner, or suffer the next ‘mix-up’. Learn to read those responses. Recognize how poweful the corner is. Once there they can no longer cause you to whiff realistically and their options are cut in half forcing them to take a risk again to escape.

One final note, I think a lot of problems with wanting to be offensive come from online. A lot of players are reversal happy, and a lot of players like to mash jab. Coupled with a couple frames of lag and you’ll get hit even when you thought you were cool. This makes people hesitant. Its hard to say if you don’t have another outlet, but try not to get caught up in learning to play ‘online-fighter.’

Add this to your arsenal:
Walk up, level 2 focus, release.